Patents Assigned to DuPont Canada Inc.
  • Patent number: 4976862
    Abstract: A process for removing blowing agent from polymeric foam. The process comprises breaking up the foam in a liquid medium to obtain a solid phase of polymeric fragments and a liquid phase of blowing agent and liquid medium. The polymeric particles are then separated from said liquid phase.
    Type: Grant
    Filed: April 10, 1989
    Date of Patent: December 11, 1990
    Assignee: Dupont Canada Inc.
    Inventors: Michael R. Ascough, James A. Bueley
  • Patent number: 4872880
    Abstract: A process for the dyeing of polymers of propylene, butene-1 and 4-methyl-pentent-1 is disclosed. The process involves contacting articles of the polymer with an aqueous dyebath containing a basic dye in a concentration of at least 0.4 g/l and at a pH of at least 5.0. The temperature of the aqueous dyebath is at least 90.degree. C. The article is maintained in contact with the dyebath for at least 10 minutes. The polymer of propylene is preferably a blend of 50-99 parts of a homopolymer of propylene or copolymer of propylene and ethylene with 1-50 parts of a zinc ionomer or graft copolymer of a hydrocarbon alpha-olefin with an alpha-olefin having carboxylic acid or carboxylic acid anhydride. Dyed polymers are obtained.
    Type: Grant
    Filed: October 6, 1988
    Date of Patent: October 10, 1989
    Assignee: DuPont Canada Inc.
    Inventor: John R. B. Boocock